Rubbing machine



June 29,1926. 1,590,353

G. H. EKSTROM RUBBING MACHINE Filed June 11, 1923 2 sneejcs-shut 41 nle Patented June 29, 1926.

UNITED, srAras ear sur oFF rc1-3;

GSTAF H. EKSTROM, OIE' ROCKFORD, ILLINOIS; ASS'IGrlNTOIB,v T0 C. lL-JX'.;i PRKEB', TRUSTEE, OF EVANSTON, ILLNOIS.

RUBBING MACHINE.

Y Application filed.` Junef11, 1923.

The invention relates to rubbing and pol'- ishing machines, and more particularly to machines operated by a pressure fluid and having a plurality of laterally spacedkpistonsfor reciprocating a corresponding numbergof pad holders. l

Theprimary object ofy the; invent-ionisi to provideY an improved rubbingg machine adapted'- fcl; ai wide-irange, of use which is fr eei from, objecti'onable' vibration 'and'v side wobbl'e'when inl operation. i

Machines in-which the rubbing-pads are arranged to reciprocate sideV by side and in which'each. pad moves: with and in theasame V direction as 'the pistOir directly above; it,

are particularlyv subject tosuch; vibration Thisv condition has` been ameliorated in certain prior machinesby connecting; each pad holder slide to the pistonA above the opposite slide, thereby making-the construction more complex and increasing theinternal friction of the machine. Ani object of the: present invention is to provide a rubbing machine which is free from objectionable vibration, and in which the rubbing pads-are-recipr04 cated, side by side respectively-by the pistons directly above them. A furtherv object is to providev a novel pad holder slide and enclosing guideway therefor which issimple in construction, and which materially reduces the distance between the pistons and the rubbing pads, as found in prior machines of this type, whereby the eiliciency of operation and the stability of the machine are increased.

Further objects and advantages will become apparent asthe description.proceeds. VIn the accompanying drawings, Figure 1 is a longitudinal sectional view on rline l.-l of Fig. 2 through a rubbing machinev embodying the -features of my invention. Fig. 2' is an end View; Fig. 3 isla transverse sectional view takenl on line of Fig. 11. Fig. l is a horizontal sectional view talren r on'linea-ll of-F-ig; 8; VFig. isahorizontal sectional view-taken on IineZ- of'Fig. l'. Fig. Gsfa horizontalsectional view'taken onllin-e (SL-def Fig. l.; Fig. V7 is: av horizontal'` sectional viewV taken` on line 7-7' of l. Y

In the: exemplary form of my: invention shown'inV thedrawings,` af cylinderbodyl 10 of: elongated rectangularA shape; isf. provided witlif 'upstalldngliagdle Wllflbly th? Serial No. 644,566.

machine can be easily carried from place to place. The lateral walls of the body prefT erably are grooved as at 12 to facilitate gripping themachine and holding ityagainst thework. Cylindersl and: lll, in parallel horizontall relation, extend through the body lOfrom end; t0... end, and; are-closedfby weight-ed end, plates;` 1 5 whichare secured lapdownwardly extending projections25 formed on pad holder slides 26, and are pivoted thereto by serew bolts 25?L passing throughthe alternating projections. and lu s. Thisl pivotal attachmentallows.alat7 era rocking of the. pad holders,v which is desirablewhen working on curved surfaces Since; the, pand` holders. are. also arranged to reciprocate side by side, the machine-is particularly adapted for work on curved' surfaces.

E ach pad holder slide 26 consists of a hor1zontal rectangular plate 27` preferably ofthe same length as. that of the pistons. The top of the plate 27 is formed with a serrated, or saw-tooth bearing surface 28 throughoutits length which engages a com.- plementary serratedv bearing surface 29 formed on the-underside ofY the cylinder body 10. In the present instance, the serrated surface, 29 isA formed on a bearing plate 30 secured'in any.suitablemannerto the underside'` of; the cylinder body and; hav;- mg thesame horizontald-mensions. AA gib platefl', having: its sidesfbent upto. f Oslm; Elv channel,s ,secured-. to; ai1dlts1-;oyer,` the-loner portionofv the; cylinder: body: lill- 3115i lweighted ends-s 15.5 and enclcses.theeplatell) and slides; 26;;4v thereby; keeping; foreign.. mail`v teraway from-the. bear-ngsi1rfacese The lugs- 25 on the; Slides'g26V extend tllirou-glr reciprocate,- in elongated reetangu'larv slots, 32 inthe gbfplate 331 (Sesma T),

Each slide 26 is centrally bored as at 33 for the recept-ion of the lower end of a connecting pin 34, the upper end of which enters a medial bore 35 in the piston directly above said slide. Each pin extends through a separate slot 36 in the bearing plate 30, and has an enlarged central portion 37 which reciprocates therein.

Any suitable means may be employed to keep the reciprocating parts in balanced relation. l have herein shown an oscillating wobbler 38 having a peripheral tlange bearing 39 and a reduced shank 40 extending upwardly therefrom. The wobblerBS is mounted within the hollowed lower portion of the cylinder head 10 and just above the bearing plate 30, and is pivotal about an aXis between the pistons and substantially midway of their ends. The flange portion 39 has a diametrical guideway al in which are slidably disposed two bearing blocks i-2, one below each piston. The connecting pins 3a pass through openings 43 in the bearing blocks before entering the hores 35. in the pistons. Reciprocation of thepistons effects an oscillation of the wobbler 38 and causes the pins Se to move the bearing blocks 4t2 radially in the diametrical gui'deway 41, thereby maintaining a balanced relation between the reciprocating parts at all times.

T he pistons 17 and 18 are holloweo at their ends as at ist to reduce their weight. Central balancing plugs 45 secured to the inner sides of the weighted ends' 15 by screw bolts 4G extend into the open ends of the pistons.

j Any suitable means may be employed f or governing the alternate admission of pressure liuid to opposite ends of the cylinders forfre'ciprocating the pistons. l have herein shown an oscillatory valve i7 seated in a 'bushing 48 co-axially above the reduced shank 40 ofthe wobbler 38. The valve is provided with a bifurcated lower end Al) fit ting loosely over a projection on the end of the-shank 110 so asto be oscillated by the lat-ter. The loose connection between the bifurcated end 49 and the projection 50 results in a lost motion, so that the pistons must travel a certain portion of their return stroke before thev valve is oscillated. Pressure fluid is admitted to the valve 1T through av passage (not shown) in the handle 11 which is under the control of a liuid valve lever 51. The fluid passes downwardly through passages 52 and 53 in the valve, and by oscillation of the latter will be admitted either through passages 54 and 55 or through passages 56 and 5./ to diagonally opposite ends of the cylinders 13 and 14.

vLongitudinal grooves 58 on the periphery of the balancing plugs 45 admitv the iiuid to the inside of thephollowed ends of the pistons. 0n the exhaust strokes, the fluid in the respective cylinders will b'edischarged through valve ports-59,; haast passages 60 the cylinder body, and downwardly extending passages 6l in the end plates 15 and gib plates 31, opening above the pad holders.

T he pistons, slides and enclosing structure for the latter have been made as light in weight as possible, while the ends of the rubbing machine have been increased in weight by use of heavy end plates and bal-A ancing plugs. rlhus the total weight of the machine, without being materially increased over that of prior constructions, is distributed to those points where it is most effective in preventing the side wobble and vibration, ordinarily due to the reciprocat-ion of the pistons and slides. A rubbing machine free from objectionable vibration is therefore obtained in which the pad holder slides are connected to and move in the same direction as the pistons directly above them.

The simple and novel construction of the pad holder slides and their enclosing structure is such that the vertical dimension of the machine and the distance betweenl the pistons and the'rubbing pads is materially less than in prior machines of this type, therebyincreasing the eiiiciency of the machine by increasing its stability and by reducing the leverage ofthe pad resistance on the pistons. VThe machine because of the rocking pad holders which are arranged to reciprocate side by side is particularly adapted for work on curved surfaces. A rubbing machine is therefore obtained which is adapted for a wide variety of uses, Vand which is simple in construction and eiticient in operation.

While I have described the preferred embodiment of my invention with considerable particularity for purposes of illustration, it is to be understood that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims.

I claim as my invention:

1. A portable rubbing machine having, in combination, a motor body having a plurality of laterally spaced cylinders, a pair of pistons, one reciprocable in each cylinder, said pistons having open hollow ends, weighted end members mounted onthe kends of said body, and plugs mounted on said end members and extending into said hollow end of said pistons, said weighted end members and said plugs serving to reduce side wabble and peripheral vibration resulting from reciprocation of said pistons.

2. A portable rubbing machinehaving, in combination, a motor body having a plurality of laterally spaced cylinders, a pair of pistons, one reciprocable in each cylinder, said pistons having open hollovs'7 ends,

Aweighted end-members mounted onthe ends of said body, each member serving t0 Vclose the endsfofbh cylinders at. eachi'end ofv 'said body, and plugs mounted on said end members and extending into said hollow ends of said pistons, said Weighted end members and said plugs by reason of their Weight and location serving to oppose side wabble and vibration. Y

3. A rubbing machine having, in Combination, a motor body having a plurality of laterally spaced Cylinders, a pair of pistons, one reeiprooable in each cylinder, Weighted end members mounted on the euds of said body, pad holder slides mounted on the underside of said body, means operatively oonnecting said pistons and said pad holder` slides, and a relatively thin gib plate fitting 15 resulting from the construction or" said heavy 20 Weighted ends and said gib plate serving to oppose vibration and side Wabble.

In testimony whereof, I have hereunto aiXed my signature.

GUSTAF H. EKSTROM. 

